LISA Montgomery is to be executed today by lethal injection in the Indiana federal death chamber.

Montgomery’s crimes are so ghastly, it might be easier, if you haven’t investigated the details of her life, to simply look away as she dies, even if you oppose capital punishment; to let America’s terrible appetite for retributive justice take its course, without raising your voice.

But you’re either against the death penalty or you’re not. You cannot oppose execution today, then decide tomorrow that some crimes are so horrific your sense of morality can be suspended.

My personal beliefs are founded upon my own human frailty. Like you, I’m just a flawed creature. The law is created by humans like us – and so our justice system is inevitably flawed too. If the law can err, then it must never be given the power to take life.

We all like to think we hold ourselves to high moral standards, but do we? Or are we just lucky? If I’d been beaten and abused as a child, might I be a murderer today instead of a writer? No child is born evil. Evil is done to children and turns them into adults who do evil themselves.

I don’t come at this from a Christian perspective. I don’t need a god to adjudicate right from wrong. Nor do I make any claims of phoney, self-righteous pacifism. If my life was threatened, I’d use violence to protect myself; if someone killed a loved one, I’d want to kill them.

And that, at heart, is why I oppose the death penalty: we’re all weak, fallible humans. The state – whether British or American – has to be better than you and I, and our flawed humanity. The state must never be emotional, angry, or vengeful, otherwise we descend into judicial barbarism. The state must be above human folly, and so it can never be given the power to kill its citizens. All killing is wrong. The state must reflect that in its own actions.

Montgomery’s path to Death Row was paved for her by others in her childhood, but the crime for which she was sentenced to death took place in 2004. Please be warned, what follows is distressing. Using a false identity, Montgomery befriended a woman called Bobbie Jo Stinnett online, chatting about dogs. Ms Stinnett was pregnant. Montgomery later drove from her home in Kansas to ostensibly look at puppies Ms Stinnett owned. Montgomery attacked Stinnett, strangled her, and cut the baby, a girl, from her womb.

Montgomery fled the scene with the baby, but was quickly tracked down and found cradling the infant. The little girl was returned to her family.

As is so often the case in America – especially when a defendant is poor and uneducated – Montgomery received an inadequate defence. One of her lawyers had never defended a capital case, the other had more clients on federal Death Row than any other American defence attorney. Montgomery’s legal team tried to claim she suffered from pseudocyesis, the delusion that Stinnett’s baby was her own. The jury found her guilty. Some limited evidence, suggesting Montgomery was a victim of physical abuse, was introduced during the sentencing phase, but it in no way seemed an excuse for the heinous murder she’d committed. She was sentenced to die.

In the intervening years, however, a mountain of evidence has come to light showing just how severe the abuse suffered by Montgomery as a child was; doctors and psychologists say she endured years of systematic torture. Again, please be warned that details of what Montgomery suffered are extremely distressing.

At three years old, she’d lie in bed while her half-sister was raped by a babysitter beside her. At 11, Montgomery’s stepfather began raping her. He built a room on the side of the family trailer so he could rape the child as and when he pleased. He beat her sadistically, causing her brain injury. When Montgomery’s mother discovered the rapes, she blamed the child, holding a gun at her head and screaming: “How could you do this to me?”

The abuse intensified, with her stepfather inviting friends to gang-rape the child. The men would urinate on her. Montgomery’s mother took part in the abuse as well, selling her daughter to tradesmen in return for odd jobs.

Montgomery’s abuse continued into adulthood. Tapes were found of Montgomery’s husband raping and beating her. The images were described as a “scene out of a horror movie”. At the time of the killing, Montgomery showed signs of severe mental illness – including dissociation from reality and fantasies about false pregnancies.

Sandra Babcock, faculty director of the Cornell Centre on the Death Penalty Worldwide and a consultant to Montgomery’s legal team, says: “This is a story about a woman who is profoundly mentally ill as a result of a lifetime of torture and sexual violence. Lisa is not the worst of the worst – she is the most broken of the broken.”

Montgomery’s crime was monstrous, but the crimes she suffered were also monstrous. There were plenty of warning signs that Montgomery was a victim throughout her life – all were ignored.

Would it be more merciful to confine her to a mental hospital than a prison? Most probably – certainly, execution isn’t the answer. I’ve no idea what kind of human I’d be if I'd endured what Montgomery endured. Perhaps I’d have maintained some decency. Perhaps I’d have killed myself – or others.

Montgomery will die in the federal death chamber. She’ll become the first woman executed by the US Government in almost 70 years. Unsurprisingly, as his presidency ends amid violence and chaos, Donald Trump is planning to kill three prisoners over four days, Montgomery included. His ghastly curtain call.

While the families of victims of crime rightly, understandably, demand justice in all its severity, Montgomery’s case, in all its complexity and horror, calls out to mercy.

As an aside, we should remember that with Britain now out of Europe, there’s currently nothing to legally prevent the reintroduction of capital punishment – something a majority of the population backs. Note that when Priti Patel became Home Secretary she had to distance herself from past comments supporting the death penalty.

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